Commerical Suborbital Point-to-Point

[simonbp]

Since it came up in the XCOR thread, but wasn't really relevant there, this deserves it's own thread.

IMHO, you could pull it off for transoceanic flights, where you don't have to worry about shocks and can economically limit yourself to a small number of hub airports (thus limiting the ground infrastructure). To make it profitable, you'd want a pretty large aircraft (think 777-class, 300-400 seats) that could fly at least once per day. There's nothing fundamentally impossible about this, but it's like no vehicle that has ever flown, or is even in serious planning.

Plus, as Jon noted on the other thread, there would be serious regulatory hurtles. Transoceanic flight are somewhat better for this, as they can take off under jets, ignite the rocket over water, and then slow to subsonic before making landfall. But it would still be an entirely new regulatory regime...

[go4mars]

Like if the second stage on a stratolaunch rocket was a passenger unit instead? 

Would the passenger compartment be a glider?  Nearly wingless and propulsively landed? 

[Robotbeat]

Only chance is to market it to those who are crazy rich. Of course, then you'd need incredible safety, as well.

[A_M_Swallow]

To make it profitable, you'd want a pretty large aircraft (think 777-class, 300-400 seats) that could fly at least once per day. {snip}

That seems a bit large.  There may only be 40-50 people a day who can afford the fare.  The number of people flying first class and business class may give an estimate.

[dcporter]

The main trouble I've heard with point to point suborbital is that the dV required for any decent down range capacity is close enough to orbital that you might as well be trying to go to LEO. So it might work out, but not for a while, and not at prices significantly lower than launching the same mass.

(This is what I've heard.)

[Blackjax]

The main trouble I've heard with point to point suborbital is that the dV required for any decent down range capacity is close enough to orbital that you might as well be trying to go to LEO. So it might work out, but not for a while, and not at prices significantly lower than launching the same mass.

(This is what I've heard.)

I have no opinion on whether Commerical Suborbital Point-to-Point is feasible, but I do wonder if the fact that you don't need some systems required in LEO but not for a brief suborbital trip would help loosen the requirements some.  You don't need multi day ECLSS or heat shielding among other things.  How would that, combined with at least a slightly lower fuel load translate to wiggle room in the difficulty of making a vehicle?

[Robotbeat]

The main trouble I've heard with point to point suborbital is that the dV required for any decent down range capacity is close enough to orbital that you might as well be trying to go to LEO. So it might work out, but not for a while, and not at prices significantly lower than launching the same mass.

(This is what I've heard.)

I have no opinion on whether Commerical Suborbital Point-to-Point is feasible, but I do wonder if the fact that you don't need some systems required in LEO but not for a brief suborbital trip would help loosen the requirements some.  You don't need multi day ECLSS or heat shielding among other things.  How would that, combined with at least a slightly lower fuel load translate to wiggle room in the difficulty of making a vehicle?

You would need something approaching a heat shield at the delta-vs needed for significant distance point-to-point (i.e. 5-6km/s or more).

[Kaputnik]

Is SOPTP supposed to be a joy-ride, or a viable means of rapid transport?
If the latter, surely the test of whether it has any utility is in whether it can delvier a person to their destination faster than alternative methods.
To achieve that, you need to avoid hours of turnaround time with passengers strapped in and awaiting launch. You need flights directly to useful destinations. And you need flights to be happening often enough that your customers don't just get on the next conventional airliner instead.

[douglas100]

As always, it comes down to whether there will be a market for it. The fact that  proposed supersonic bizjet projects have yet to succeed suggests that presently there is not enough demand for personal high speed travel. This may change of course.

I think commercial suborbital point-to-point is more likely to succeed starting small and targeting niche markets (as was suggested on the XCOR thread.) I think 777 sized vehicles are a completely unrealistic starting point.

Suborbital mass passenger travel also could potentially face serious competition in the medium term from hypersonic vehicles like LAPCAT if they are ever developed.

[go4mars]

The fact that  proposed supersonic bizjet projects have yet to succeed suggests that presently there is not enough demand for personal high speed travel.

As far as I know, the only credible biz-jet proposals were limited to about mach 1.7, didn't provide the novelty of several weightless minutes, were relatively limited range, and sonic booms were still a constraining issue for route choices because they couldn't bypass the atmosphere between take-off town and landing-land.  Not a useful comparison imo. 

[douglas100]

I think it's a correct comparison. If developers of supersonic bizjets are unable to bring their aircraft to market currently, then I suggest there is insufficient demand for faster passenger flight at the present time.

The sonic boom issue is not a show stopper if the SST flies high enough. I don't think that is what is preventing the introduction of such aircraft.

Commercial point-to-point is not about providing the novelty of weightlessness, it's about delivering people or goods rapidly around the planet. Weightlessness as a selling point is part of space tourism for which the market demand is currently being addressed.

There are regulatory hurdles to be overcome for suborbital vehicles as Jon Goff pointed out in another thread. Flying them out of commercial airports is problematical.

If you think there will be a large demand for suborbital passenger services in the near future, I would like to hear your arguments.

[simonbp]

To make it profitable, you'd want a pretty large aircraft (think 777-class, 300-400 seats) that could fly at least once per day. {snip}

That seems a bit large.  There may only be 40-50 people a day who can afford the fare.  The number of people flying first class and business class may give an estimate.

Well that's the point. Most of the cost of operating the aircraft is in the fixed infrastructure and fuel. If you have the passengers to support it, you want the largest aircraft possible. A 747 is not cheap per flight, but it is cheap per seat, and that's what makes transatlantic travel affordable.

This is not a new analysis; the American response to the Concorde was the Boeing 2707, which had about 300 seats (and probably closer to 350 in a modern configuration). This was because Boeing did the math and realized that that was the minimum size that could be expected to be profitable (Concorde maxed out at 128 passengers).

The reason I focused on transoceanic flights is because they do have the traffic to easy fill many large suborbital transports daily. Even if the only suborbital service you had was New York-London, there would be enough passengers to justify 5-10 400-seat transports (depending on how much maintenance downtime they need). Add New York-LA and LA-Tokyo and you've just cornered a large sector of the world's long-distance market.

[mrmandias]

If this happens, it will be high-value cargo with a time crunch first: rare medicines, organs, critical replacement parts for factories, documents where you have to have the originals for legal reasons, etc.  The military may also have an interest in maintaining a standby fleet of point to point vehicles capable of delivering certain kinds of "cargo"*

Passengers are more complicated.

*which, incidentally, points up some of the regulatory/legal problems with suborbital point-to-point.  How to make sure that it isn't an ICBM or illicitly used for a surprise nuclear and/or EMP attack?

[clongton]

As always, it comes down to whether there will be a market for it. The fact that  proposed supersonic bizjet projects have yet to succeed suggests that presently there is not enough demand for personal high speed travel. This may change of course.

On-Demand Commercial Sub-orbital Point-to-Point transoceanic transportation will see its first *successful* use in the military and diplomatic corps, not the commercial market. The price per seat is less of an issue than the rapid transport point to point often needed by such personnel.

So the military will adopt it first, then the diplomatic corps will make use of it and finally commercial will slowly fall in step. That's when the price will begin to come down to reasonable levels, and not before.

I fully expect to see this capability become a reality, and the above scenario is how I think it will come to be.

[Robotbeat]

How much is it worth to place (within a matter of less than an hour) a well-trained special-ops guy at the scene of a crisis with some diplomat being held hostage? Pretty high, perhaps millions of dollars.

How high would the annual demand for such flights be? It could be a very, very low number.

[go4mars]

Oil field parts to remote locations where rig time can be into 6 figures per hour.

[A_M_Swallow]

Oil field parts to remote locations where rig time can be into 6 figures per hour.

That market requires the plane to land at ordinary and small airports.

[go4mars]

If you think there will be a large demand for suborbital passenger services in the near future, I would like to hear your arguments.

Okay.  New York to London.  That's usually about 7 hours.  Add 2 hours for the front end, and another 30 minutes on the back for taxi and disembark, and wander Heathrow looking for an exit.    9.5 hours. 

Now if you are in a biz jet that goes almost twice the speed for 2/3rds of the flight, that shaves off 2.5 hours of flight time.  But the rest stays the same, so it's a 7 hour travel day instead of a 9.5 hour travel day.     Is that worth an extra few thousand bucks more than a 1st class slower ticket to a business person's schedule?  No.  They are likely to plan a whole day for travel anyways.   Who wants a bunch of meetings after that? 

If the flight time could be chopped from 7 hours to perhaps 90 minutes, then it gets a whole lot more interesting as an early morning or evening proposition.  Potentially 3.5 or 4 hours of traveling time (less if there is the equivalent of a NEXUS pass).  For a lot of frequent business-class flyers, an added day of productivity is worth a few thousand dollars.        That = potential for increased demand.  Unlike a mach 1.6 type scheme.

[go4mars]

That market requires the plane to land at ordinary and small airports.

Most drill ships don't have those.  I mean to imply propulsive landing on their heli-pads at sea. 

[douglas100]

For a lot of frequent business-class flyers, an added day of productivity is worth a few thousand dollars.        That = potential for increased demand.  Unlike a mach 1.6 type scheme.

(My bold.)

Remember I said near future and large demand. A suborbital flight for a few thousand dollars is completely unrealistic. Likewise, the operation of suborbital vehicles out of large suburban airports is completely unrealistic in the near future. Suborbital point-to-point will start as a small, infrequent, extremely expensive service.

Clongton's,  Robotbeat's and mrmandias's scenarios make more sense.